The present invention relates to variable displacement axial piston pumps and pertains particularly to a variable displacement axial piston pump having displacement control means which are automatically operative to maintain and infinitely vary displacement of said pump.
Variable displacement pumps are often utilized in earth moving and other heavy duty machinery because pump flow and system pressure can be varied to meet system demands. Such variable displacement pumps are often equipped with pressure compensator controls for controlling or varying pump output pressure in response to system pressure.
A number of control systems are known which rely on load pressure of the system for controlling the displacement of the pump. However, these prior art systems fail to include sufficient variables to insure precise and continuous control of the displacement.
The prior art is exemplified by the following patents: U.S. Pat. No. 2,892,312 which issued to J. R. Allen et al on June 30, 1959, from an application filed on Jan. 27, 1958, and which is assigned to Deere & Company; U.S. Pat. No. 3,834,836 which issued to Allyn J. Hein et al on Sept. 10, 1974, from an application filed on Mar. 1, 1973, which is assigned to the assignee hereof; U.S. Pat. No. 3,797,245 which issued to Allyn J. Hein on Mar. 19, 1974, from an application filed on Aug. 25, 1972, which is assigned to the assignee hereof.